Of these two stories, the more believable is Joran's. If Natalee and Joran were dropped off at the beach, we must believe that this 17 year old in the middle of the night murdered her there with no weapons, disposed of her body with no tools, then walked back home. This disposal was so effective that it has eluded the determined efforts of many searchers for two weeks. Not very likely.
That the body hasn't been found means that Natalee was transported elsewhere and murdered where disposal was convenient, or that the body was transported to its disposal site. Either requires a car, which implicates the car's owners.
So, either the brothers were involved with Jaron, or without Jaron, but the brothers had to be involved, they had the keys.
I think the beach is the key. The beach is the place where a man can feel he's the only soul in the world that's real. The beach cleans up after itself. If it was the area where they feed the sharks and the tide was right...
Transporting the body would have been quite a problem. Even feeding the sharks I'm surprised remnants of clothing haven't turned up. Or is it known what she was wearing? (I realize that's a stupid question, just pointing out they don't tell us much up here in the States.)
" Of these two stories, the more believable is Joran's."
You're right about that. This has been bothering me, too. Without any tools it would have been hard to bury her. But we don't know if there are any natural hiding places around that spot (wells, for instance) that he could use to dispose of a body. Also, we don't know what the tides were like that night. He's certainly big and strong enough to carry her into the ocean. Just thinking Aloud.
I think they are all in on it together.